Procedures for monitoring fish food consumption

Abstract

Procedures for feeding fish or crustaceans are disclosed which make possible monitoring the extent to which the administered food is actually eaten. These procedures utilize fluorescent dyes which are commingled with the food in order by their release into the culture water to indicate the extent to which the feed is being eaten. By administering food containing fluorescent dyes which when eaten cause the culture water to fluoresce, a direct measure of the food eaten is achieved. By administering food containing fluorescent dyes which when not eaten cause the culture water to fluoresce, a direct measure of the extent of wasteful overfeeding is achieved. By administering food containing both types of fluorescent dyes simultaneously, and measuring the ratio of their fluorescences, a sensitive measure of feeding activity is achieved.

I claim: 
     
       1. A method for determining the proper amount of food for consumption by a culture of fish and/or crustaceans comprising the steps of: a. spiking food with non-toxic fluorescent dyes;   b. administering a pre-determined amount of said spiked food to said culture;   c. allowing sufficient time for said spiked food to be eaten;   d. exposing water from said culture to light near or at the maximum absorption wavelength of said dye(s);   e. measuring the intensity of the fluorescence of said culture water at or near the maximum emission wavelength(s) of said fluorescent dye(s); and,   f. adjusting the amount of food administered to said culture, according to said measurement(s).   
     
     
       2. The method of claim 1 wherein said fluorescent dye(s) are selected from the group consisting of fluorescein, umbelliferone, 6,7-dihydroxycoumarin 6-glucoside, and tetracycline. 
     
     
       3. The method of claim 1 wherein said spiking is accomplished by encapsulating said fluorescent dyes with non-toxic, water insoluble, and edible material; commingling said capsules with food stuffs; and forming said mixture into flakes or pellets. 
     
     
       4. The method of claim 1 wherein said spiking is accomplished by mechanically stirring together fine powders of said dye(s) with food stuffs; and forming said mixture into flakes or pellets. 
     
     
       5. The method of claim 1 wherein said spiking is accomplished by dissolving said fluorescent dye(s) in edible fats or oils; commingling said solution with food stuffs; and forming said mixture into flakes or pellets. 
     
     
       6. The method of claim 1 wherein said fish are edible catfish and salmonids. 
     
     
       7. The method of claim 1 wherein said crustaceans are edible shrimps, prawns, or lobsters. 
     
     
       8. The method of claim 1 wherein said culture occupies an aquarium. 
     
     
       9. A method for determining whether or not food administered to a culture of fish and/or crustaceans is actually being eaten by said culture, said method comprising the steps of: a. spiking food with at least two non-toxic fluorescent dyes, where at least one of said dyes becomes less fluorescent on being eaten by said culture;   b. administering a pre-determined amount of said spiked food to said culture;   c. exposing water from said culture to light containing the excitation wavelengths of said dyes; and,   d. monitoring the ratio(s) of the intensities of the fluorescences of said dyes.   
     
     
       10. The method of claim 9 wherein said dyes are fluorescein and umbelliferone. 
     
     
       11. The method of claim 9 wherein spiking is accomplished by encapsulating said fluorescent dyes; commingling said capsules with food; and forming said mixture into flakes or pellets. 
     
     
       12. The method of claim 9 wherein said spiking is accomplished by dissolving said fluorescent dyes in edible fats or oils; commingling said solution with food stuffs; and forming said mixture into flakes or pellets. 
     
     
       13. The method of claim 9 wherein said spiking is accomplished by commingling fine powders of said dyes with food stuffs; and forming said mixture into pellets or flakes. 
     
     
       14. The method of claim 9 wherein said culture is enclosed in a cage or raceway.